Download Exam #4

Math 154A/Payne
Angel/Exam 4 Review/Chapter 4
Your exam will be on Wednesday, April 22nd. It will cover Chapter 4 and have a value of 100
points. You will have the entire time, lecture and lab, to take the exam. That’s 2 hours, 5
minutes. It will model the Chapter 4 Practice Test in your book on page 296, problems 1 – 17.
You need to be able to:
1. identify the parts of the Cartesian (rectangular) coordinate system.
2. determine if an ordered pair is a solution to (satisfies) a given equation.
3. by looking at the graph of a line, determine if the slope is positive, negative, zero, or
undefined.
4. given two ordered pairs, calculate the slope.
5. determine the slope of a line from its graph.
6. given two equations, (or two slopes), determine if they represent parallel lines, perpendicular
lines, or neither.
7. rewrite an equation, putting it into slope-intercept form (y = mx + b), and identify the slope
and the y-intercept.
8. write an equation given its graph.
9. graph linear equations is all their forms, including horizontal and vertical lines, using the
three techniques of point-plotting, x- and y-intercepts, and slope and y-intercept .
10. write in slope-intercept form (y = mx + b) the equation of a line given its slope and a point on
the line. (Remember you have to start with point-slope form: y – y1 = m(x – x1))
11. write the equation of a line given two points on the line. (Remember here you have to start
by calculating the slope, and then use point-slope form before you can end with slopeintercept form.)
Formulas to remember:
A.
Slope formula:
y 2  y1
m
x 2  x1
parallel lines have equal slopes
perpendicular lines have opposite reciprocal slopes
B. Forms of Linear Equations in Two Variables
1) Standard Form: ax + by = c
2) Horizontal line crossing the y-axis at b: y = b (slope is 0)
3) Vertical line crossing the x-axis at a: x = a (slope is undefined)
4) Slope-Intercept Form: y = mx + b
5) Point-Slope Form: y  y 1  m( x  x 1 )
C.
When finding the equation of a line, begin with the
1) slope-intercept form if you know
a) the slope of the line and the y-intercept.
2) point-slope form if you know
a) the slope of the line and a point on the line, or
b) two points on the line (first find the slope, then use the point-slope form)